//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2010 Greenplum, Inc.
//
//	@filename:
//		CParseHandlerHashExpr.cpp
//
//	@doc:
//		Implementation of the SAX parse handler class for parsing hash expression operators.
//---------------------------------------------------------------------------

#include "naucrates/dxl/parser/CParseHandlerHashExpr.h"
#include "naucrates/dxl/parser/CParseHandlerScalarOp.h"

#include "naucrates/dxl/operators/CDXLOperatorFactory.h"
#include "naucrates/dxl/parser/CParseHandlerFactory.h"

using namespace gpdxl;


XERCES_CPP_NAMESPACE_USE

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerHashExpr::CParseHandlerHashExpr
//
//	@doc:
//		Constructor
//
//---------------------------------------------------------------------------
CParseHandlerHashExpr::CParseHandlerHashExpr
	(
	CMemoryPool *mp,
	CParseHandlerManager *parse_handler_mgr,
	CParseHandlerBase *parse_handler_root
	)
	:
	CParseHandlerScalarOp(mp, parse_handler_mgr, parse_handler_root),
	m_dxl_op(NULL)
{
}


//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerHashExpr::StartElement
//
//	@doc:
//		Invoked by Xerces to process an opening tag
//
//---------------------------------------------------------------------------
void
CParseHandlerHashExpr::StartElement
	(
	const XMLCh* const, // element_uri,
	const XMLCh* const element_local_name,
	const XMLCh* const, // element_qname
	const Attributes& attrs
	)
{
	if(0 != XMLString::compareString(CDXLTokens::XmlstrToken(EdxltokenScalarHashExpr), element_local_name))
	{
		CWStringDynamic *str = CDXLUtils::CreateDynamicStringFromXMLChArray(m_parse_handler_mgr->GetDXLMemoryManager(), element_local_name);
		GPOS_RAISE(gpdxl::ExmaDXL, gpdxl::ExmiDXLUnexpectedTag, str->GetBuffer());
	}
	
	// parse and create hash expr operator
	m_dxl_op = (CDXLScalarHashExpr *) CDXLOperatorFactory::MakeDXLHashExpr(m_parse_handler_mgr->GetDXLMemoryManager(), attrs);
	
	// create and activate the parse handler for the child scalar expression node
	
	CParseHandlerBase *op_parse_handler = CParseHandlerFactory::GetParseHandler(m_mp, CDXLTokens::XmlstrToken(EdxltokenScalar), m_parse_handler_mgr, this);
	m_parse_handler_mgr->ActivateParseHandler(op_parse_handler);
	
	// store child parse handler
	this->Append(op_parse_handler);
}

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerHashExpr::EndElement
//
//	@doc:
//		Invoked by Xerces to process a closing tag
//
//---------------------------------------------------------------------------
void
CParseHandlerHashExpr::EndElement
	(
	const XMLCh* const, // element_uri,
	const XMLCh* const element_local_name,
	const XMLCh* const // element_qname
	)
{
	
	if(0 != XMLString::compareString(CDXLTokens::XmlstrToken(EdxltokenScalarHashExpr), element_local_name))
	{
		CWStringDynamic *str = CDXLUtils::CreateDynamicStringFromXMLChArray(m_parse_handler_mgr->GetDXLMemoryManager(), element_local_name);
		GPOS_RAISE(gpdxl::ExmaDXL, gpdxl::ExmiDXLUnexpectedTag, str->GetBuffer());
	}
	
	CParseHandlerScalarOp *op_parse_handler = dynamic_cast<CParseHandlerScalarOp *>((*this)[0]);
	
	GPOS_ASSERT(NULL != op_parse_handler->CreateDXLNode());
	
	// construct node from the parsed expression node
	m_dxl_node = GPOS_NEW(m_mp) CDXLNode(m_mp, m_dxl_op);	
			
	AddChildFromParseHandler(op_parse_handler);
	
	// deactivate handler
	m_parse_handler_mgr->DeactivateHandler();
}

// EOF
